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<FONT color="green">001</FONT>    /*<a name="line.1"></a>
<FONT color="green">002</FONT>     * Licensed to the Apache Software Foundation (ASF) under one or more<a name="line.2"></a>
<FONT color="green">003</FONT>     * contributor license agreements.  See the NOTICE file distributed with<a name="line.3"></a>
<FONT color="green">004</FONT>     * this work for additional information regarding copyright ownership.<a name="line.4"></a>
<FONT color="green">005</FONT>     * The ASF licenses this file to You under the Apache License, Version 2.0<a name="line.5"></a>
<FONT color="green">006</FONT>     * (the "License"); you may not use this file except in compliance with<a name="line.6"></a>
<FONT color="green">007</FONT>     * the License.  You may obtain a copy of the License at<a name="line.7"></a>
<FONT color="green">008</FONT>     *<a name="line.8"></a>
<FONT color="green">009</FONT>     *      http://www.apache.org/licenses/LICENSE-2.0<a name="line.9"></a>
<FONT color="green">010</FONT>     *<a name="line.10"></a>
<FONT color="green">011</FONT>     * Unless required by applicable law or agreed to in writing, software<a name="line.11"></a>
<FONT color="green">012</FONT>     * distributed under the License is distributed on an "AS IS" BASIS,<a name="line.12"></a>
<FONT color="green">013</FONT>     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.<a name="line.13"></a>
<FONT color="green">014</FONT>     * See the License for the specific language governing permissions and<a name="line.14"></a>
<FONT color="green">015</FONT>     * limitations under the License.<a name="line.15"></a>
<FONT color="green">016</FONT>     */<a name="line.16"></a>
<FONT color="green">017</FONT>    <a name="line.17"></a>
<FONT color="green">018</FONT>    package org.apache.commons.lang3.event;<a name="line.18"></a>
<FONT color="green">019</FONT>    <a name="line.19"></a>
<FONT color="green">020</FONT>    import java.lang.reflect.InvocationHandler;<a name="line.20"></a>
<FONT color="green">021</FONT>    import java.lang.reflect.InvocationTargetException;<a name="line.21"></a>
<FONT color="green">022</FONT>    import java.lang.reflect.Method;<a name="line.22"></a>
<FONT color="green">023</FONT>    import java.lang.reflect.Proxy;<a name="line.23"></a>
<FONT color="green">024</FONT>    import java.util.Arrays;<a name="line.24"></a>
<FONT color="green">025</FONT>    import java.util.HashSet;<a name="line.25"></a>
<FONT color="green">026</FONT>    import java.util.Set;<a name="line.26"></a>
<FONT color="green">027</FONT>    <a name="line.27"></a>
<FONT color="green">028</FONT>    import org.apache.commons.lang3.reflect.MethodUtils;<a name="line.28"></a>
<FONT color="green">029</FONT>    <a name="line.29"></a>
<FONT color="green">030</FONT>    /**<a name="line.30"></a>
<FONT color="green">031</FONT>     * Provides some useful event-based utility methods.<a name="line.31"></a>
<FONT color="green">032</FONT>     *<a name="line.32"></a>
<FONT color="green">033</FONT>     * @since 3.0<a name="line.33"></a>
<FONT color="green">034</FONT>     * @version $Id: EventUtils.java 1091072 2011-04-11 13:42:03Z mbenson $<a name="line.34"></a>
<FONT color="green">035</FONT>     */<a name="line.35"></a>
<FONT color="green">036</FONT>    public class EventUtils {<a name="line.36"></a>
<FONT color="green">037</FONT>    <a name="line.37"></a>
<FONT color="green">038</FONT>        /**<a name="line.38"></a>
<FONT color="green">039</FONT>         * Adds an event listener to the specified source.  This looks for an "add" method corresponding to the event<a name="line.39"></a>
<FONT color="green">040</FONT>         * type (addActionListener, for example).<a name="line.40"></a>
<FONT color="green">041</FONT>         * @param eventSource   the event source<a name="line.41"></a>
<FONT color="green">042</FONT>         * @param listenerType  the event listener type<a name="line.42"></a>
<FONT color="green">043</FONT>         * @param listener      the listener<a name="line.43"></a>
<FONT color="green">044</FONT>         * @param &lt;L&gt;           the event listener type<a name="line.44"></a>
<FONT color="green">045</FONT>         *<a name="line.45"></a>
<FONT color="green">046</FONT>         * @throws IllegalArgumentException if the object doesn't support the listener type<a name="line.46"></a>
<FONT color="green">047</FONT>         */<a name="line.47"></a>
<FONT color="green">048</FONT>        public static &lt;L&gt; void addEventListener(Object eventSource, Class&lt;L&gt; listenerType, L listener) {<a name="line.48"></a>
<FONT color="green">049</FONT>            try {<a name="line.49"></a>
<FONT color="green">050</FONT>                MethodUtils.invokeMethod(eventSource, "add" + listenerType.getSimpleName(), listener);<a name="line.50"></a>
<FONT color="green">051</FONT>            } catch (NoSuchMethodException e) {<a name="line.51"></a>
<FONT color="green">052</FONT>                throw new IllegalArgumentException("Class " + eventSource.getClass().getName()<a name="line.52"></a>
<FONT color="green">053</FONT>                        + " does not have a public add" + listenerType.getSimpleName()<a name="line.53"></a>
<FONT color="green">054</FONT>                        + " method which takes a parameter of type " + listenerType.getName() + ".");<a name="line.54"></a>
<FONT color="green">055</FONT>            } catch (IllegalAccessException e) {<a name="line.55"></a>
<FONT color="green">056</FONT>                throw new IllegalArgumentException("Class " + eventSource.getClass().getName()<a name="line.56"></a>
<FONT color="green">057</FONT>                        + " does not have an accessible add" + listenerType.getSimpleName ()<a name="line.57"></a>
<FONT color="green">058</FONT>                        + " method which takes a parameter of type " + listenerType.getName() + ".");<a name="line.58"></a>
<FONT color="green">059</FONT>            } catch (InvocationTargetException e) {<a name="line.59"></a>
<FONT color="green">060</FONT>                throw new RuntimeException("Unable to add listener.", e.getCause());<a name="line.60"></a>
<FONT color="green">061</FONT>            }<a name="line.61"></a>
<FONT color="green">062</FONT>        }<a name="line.62"></a>
<FONT color="green">063</FONT>    <a name="line.63"></a>
<FONT color="green">064</FONT>        /**<a name="line.64"></a>
<FONT color="green">065</FONT>         * Binds an event listener to a specific method on a specific object.<a name="line.65"></a>
<FONT color="green">066</FONT>         *<a name="line.66"></a>
<FONT color="green">067</FONT>         * @param &lt;L&gt;          the event listener type<a name="line.67"></a>
<FONT color="green">068</FONT>         * @param target       the target object<a name="line.68"></a>
<FONT color="green">069</FONT>         * @param methodName   the name of the method to be called<a name="line.69"></a>
<FONT color="green">070</FONT>         * @param eventSource  the object which is generating events (JButton, JList, etc.)<a name="line.70"></a>
<FONT color="green">071</FONT>         * @param listenerType the listener interface (ActionListener.class, SelectionListener.class, etc.)<a name="line.71"></a>
<FONT color="green">072</FONT>         * @param eventTypes   the event types (method names) from the listener interface (if none specified, all will be<a name="line.72"></a>
<FONT color="green">073</FONT>         *                     supported)<a name="line.73"></a>
<FONT color="green">074</FONT>         */<a name="line.74"></a>
<FONT color="green">075</FONT>        public static &lt;L&gt; void bindEventsToMethod(Object target, String methodName, Object eventSource,<a name="line.75"></a>
<FONT color="green">076</FONT>                Class&lt;L&gt; listenerType, String... eventTypes) {<a name="line.76"></a>
<FONT color="green">077</FONT>            final L listener = listenerType.cast(Proxy.newProxyInstance(target.getClass().getClassLoader(),<a name="line.77"></a>
<FONT color="green">078</FONT>                    new Class[] { listenerType }, new EventBindingInvocationHandler(target, methodName, eventTypes)));<a name="line.78"></a>
<FONT color="green">079</FONT>            addEventListener(eventSource, listenerType, listener);<a name="line.79"></a>
<FONT color="green">080</FONT>        }<a name="line.80"></a>
<FONT color="green">081</FONT>    <a name="line.81"></a>
<FONT color="green">082</FONT>        private static class EventBindingInvocationHandler implements InvocationHandler {<a name="line.82"></a>
<FONT color="green">083</FONT>            private final Object target;<a name="line.83"></a>
<FONT color="green">084</FONT>            private final String methodName;<a name="line.84"></a>
<FONT color="green">085</FONT>            private final Set&lt;String&gt; eventTypes;<a name="line.85"></a>
<FONT color="green">086</FONT>    <a name="line.86"></a>
<FONT color="green">087</FONT>            /**<a name="line.87"></a>
<FONT color="green">088</FONT>             * Creates a new instance of {@code EventBindingInvocationHandler}.<a name="line.88"></a>
<FONT color="green">089</FONT>             *<a name="line.89"></a>
<FONT color="green">090</FONT>             * @param target the target object for method invocations<a name="line.90"></a>
<FONT color="green">091</FONT>             * @param methodName the name of the method to be invoked<a name="line.91"></a>
<FONT color="green">092</FONT>             * @param eventTypes the names of the supported event types<a name="line.92"></a>
<FONT color="green">093</FONT>             */<a name="line.93"></a>
<FONT color="green">094</FONT>            EventBindingInvocationHandler(final Object target, final String methodName, String[] eventTypes) {<a name="line.94"></a>
<FONT color="green">095</FONT>                this.target = target;<a name="line.95"></a>
<FONT color="green">096</FONT>                this.methodName = methodName;<a name="line.96"></a>
<FONT color="green">097</FONT>                this.eventTypes = new HashSet&lt;String&gt;(Arrays.asList(eventTypes));<a name="line.97"></a>
<FONT color="green">098</FONT>            }<a name="line.98"></a>
<FONT color="green">099</FONT>    <a name="line.99"></a>
<FONT color="green">100</FONT>            /**<a name="line.100"></a>
<FONT color="green">101</FONT>             * Handles a method invocation on the proxy object.<a name="line.101"></a>
<FONT color="green">102</FONT>             *<a name="line.102"></a>
<FONT color="green">103</FONT>             * @param proxy the proxy instance<a name="line.103"></a>
<FONT color="green">104</FONT>             * @param method the method to be invoked<a name="line.104"></a>
<FONT color="green">105</FONT>             * @param parameters the parameters for the method invocation<a name="line.105"></a>
<FONT color="green">106</FONT>             * @return the result of the method call<a name="line.106"></a>
<FONT color="green">107</FONT>             * @throws Throwable if an error occurs<a name="line.107"></a>
<FONT color="green">108</FONT>             */<a name="line.108"></a>
<FONT color="green">109</FONT>            public Object invoke(final Object proxy, final Method method, final Object[] parameters) throws Throwable {<a name="line.109"></a>
<FONT color="green">110</FONT>                if (eventTypes.isEmpty() || eventTypes.contains(method.getName())) {<a name="line.110"></a>
<FONT color="green">111</FONT>                    if (hasMatchingParametersMethod(method)) {<a name="line.111"></a>
<FONT color="green">112</FONT>                        return MethodUtils.invokeMethod(target, methodName, parameters);<a name="line.112"></a>
<FONT color="green">113</FONT>                    } else {<a name="line.113"></a>
<FONT color="green">114</FONT>                        return MethodUtils.invokeMethod(target, methodName);<a name="line.114"></a>
<FONT color="green">115</FONT>                    }<a name="line.115"></a>
<FONT color="green">116</FONT>                }<a name="line.116"></a>
<FONT color="green">117</FONT>                return null;<a name="line.117"></a>
<FONT color="green">118</FONT>            }<a name="line.118"></a>
<FONT color="green">119</FONT>    <a name="line.119"></a>
<FONT color="green">120</FONT>            /**<a name="line.120"></a>
<FONT color="green">121</FONT>             * Checks whether a method for the passed in parameters can be found.<a name="line.121"></a>
<FONT color="green">122</FONT>             *<a name="line.122"></a>
<FONT color="green">123</FONT>             * @param method the listener method invoked<a name="line.123"></a>
<FONT color="green">124</FONT>             * @return a flag whether the parameters could be matched<a name="line.124"></a>
<FONT color="green">125</FONT>             */<a name="line.125"></a>
<FONT color="green">126</FONT>            private boolean hasMatchingParametersMethod(final Method method) {<a name="line.126"></a>
<FONT color="green">127</FONT>                return MethodUtils.getAccessibleMethod(target.getClass(), methodName, method.getParameterTypes()) != null;<a name="line.127"></a>
<FONT color="green">128</FONT>            }<a name="line.128"></a>
<FONT color="green">129</FONT>        }<a name="line.129"></a>
<FONT color="green">130</FONT>    }<a name="line.130"></a>




























































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